209797986 has 16 divisors (see below), whose sum is σ = 444278304. Its totient is φ = 65818944.

The previous prime is 209797979. The next prime is 209798011. The reversal of 209797986 is 689797902.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1028320 + ... + 1028523.

It is an arithmetic number, because the mean of its divisors is an integer number (27767394).

Almost surely, 2^209797986 is an apocalyptic number.

209797986 is an abundant number, since it is smaller than the sum of its proper divisors (234480318).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

209797986 is a wasteful number, since it uses less digits than its factorization.

209797986 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2056865.

The product of its (nonzero) digits is 3429216, while the sum is 57.

The square root of 209797986 is about 14484.4049239173. The cubic root of 209797986 is about 594.2015380246.

The spelling of 209797986 in words is "two hundred nine million, seven hundred ninety-seven thousand, nine hundred eighty-six".